Loud-speaker



VA. DELPH Nov. 12, 1929.

LOUD SPEAKER Filed Dec. 30. 1926 2 Sheets-Sheet 1 Maw/aw Nov. 12, 1929.

A. DELPH noun SPEAKER Filed Dec. 30. 1926 2 Sheets-Sheet 2 And/"9w 1640/7,

gwue/ntoc Whnesses Patented Nov. 12, 1929 'UNITED STATES PATENT OFFICE LOUD-SPEAKER Application filed December 30, 1926. Serial No. 158,049.

This invention relates to a horn construction and pertains particularly to an improved type of horn for use upon talking machines or as a loud-speaker for a radio set.

The primary object of this invention, is to provide, in a manner as hereinafter set forth, a loudspeaker horn having inherent qualities for materially improving the tone of signal vibration introduced thereinto and amplifying these signals smoothly and without distortion.

Another object of the invention is to provide, in a manner as hereinafter set forth, a loudspeaker which will amplify signals passing therethrough, without imparting a harsh metallic tone thereto as is usual with loudspeakers of the type at present in use.

Numerous other objects and advantages will become apparent as the description of the invention proceeds, and the invention will be best understood from a consideration of the following detailed description taken in connection with the accompanying drawings forming a part of this specification, with the understanding however, that the invention is not confined to any strict conformity with the showing of the drawings but may be changed or modifiedso long assuch changes or modifications mark no material departure from the salient features of the invention as expressed in the appended claims.

In the drawings:

Figure 1 shows the loudspeaker embodying this invention in front elevation.

Figure 2 is a side elevational view of the speaker.

Figure 3 is a vertical longitudinal section of the structure, and Figure 4 is a transverse section taken upon the line 44 of Figure 3.

Referring now to the drawings in detail wherein like numerals of reference indicate corresponding parts throughout the several views, it will be seen that the horn structure proper comprises a plurality of nested casing bodies or horn members. The outer one of the horn members which may be termed the casing horn or box is indicated by the numeral 1. This box, like the other members associated therewith is of square cross section as shown in Figure 4, having the top and bottom walls 2 and 3 respectively and the side walls 4 and is of sound proof construction to properly confine and convey the sound to the forward end thereof. The top, bottom and side wall sections of the casing box 1 are so formed that when the same are placed together in side edge relation, a substantially frusto-pyramidal hollow body is set up which is normally supported in horizontal position by the rear bracket 5 secured to one of the walls and the forward supporting foot 6 which is located at the front or large end of the horn. A suitable carrying handle 7 may be secured to the top wall of the casing horn, in the manner shown.

Within the casing box 1 are three nested conducting horn bodies indicated generally by the numerals 8, 9 and 10. The largest of these three bodies, which is indicated by the numeral 8 is of square cross section and is of greater length than the encasing horn 1 and is positioned within the casing 1 with the front or outlet end flush with the front end of the casing. Thus the smaller end of this member extends beyond the rear end of the casing horn 1 as shown in Figure 3. This horn member 8 is also turned in the casing horn 1 in such a manner as to position each of the four side walls thereof cross-ways of each of the angles formed by the walls of the casing horn, each edge of the horn member extending along the longitudinal center of a wall of the casing horn member as shown in Figure 4. Thus there is set up four sounding chambers between the casing and horn member 8. Suitable bracket elements or blocks are interposed between the walls of the casing horn and the edg of the outer one of the three horn members, as indicated at 11, these brackets 11 being located adjacent the rear or constricted end of the horn member 8.

Suitable supporting and sound posts 12 ex tend from each corner of the casing horn adjacent the forward end thereof inwardly to contact with the adjacent wall of the horn member 8. These posts materially reduce the vibration and distortion in the instrument. A suitable binding of thin wood or other material extends about the inner face of the ill born member 8 adjacent the forward edge thereof as indicated at 13, and surrounding and extending forwardly of the forward edge of the casing 1 is a binding strip 14 which also serves to form a receiving frame for a grill frame hereinafter described.

l/Vithin the outer one of the three horn members isthe central one 9 of these members which central horn member is also of square cross section and is of materially less length and width than-thememberS as'will-be readily seen from reference to Figures 1 and 3. This central horn member 9 is set within the member 8 in such manneras .to,position each of the four walls thereof substantially parallel with the walls of the horn casing, thus bringingtheedges of this center horn member parallel with the longitudinal centers .of the walls-of the horninember 8 and this member 9 isof suiiicient width to cause the edges to bearagainst the walls of the member 8 when arranged-inithe position described.

Within and adjacentthe inner end of the central horn member 9 is positioned a pair of .cifOSsed sound posts and a binding strip (or beading ofsuitable material is formed about this'central horn member at the foilwardie dge thereof as indicated by the numeral .16.

.lYithin the centralhornmomber 9 is the inner horn member 10 whichisof substantially gent relation from theIinner-to the outer end ithan-the walls of the horn members 8 and 9.

Thisiinnermembcr 10,'as above described, is also,of square cross section andis so arranged in-the-member 9 that-each ofthe walls is substantially parallel with thciouter horn member-8,.thus arranging the edges of this member to extend longitudinally of the central portionof each wall of-thecentral horn memher ,9. The forwardedge of the inner horn Positioned within the frame formed by-the projecting portion-of the binclingistrip leis ,a double framed-grille indicated generally by the numeral 17 and comprising the inner and outer frames 18 and 19 respectively between whichis clamped an appropriate piece of inat-rial such as. cloth or the'like indicated by the numeralQO.

$ecured to'the rear end of the horn casing -1 is a tonearm or sounding chamber 21,-the

,outlet end of w iichopens laterally from the arm in the form of a coupling flange 22 which isdesigned to-be inserted in-the small and of :the horn casing 1 between the same .andithe outer one 80f the-threehorn members,

this horn member extending into the lower portion of the tone arm as shown in Figure 3. The upper end of the tone arm is provided with a collar 23 in which a phone unit 24 (Figure 2) may be engaged.

The structure embodying this invention is preferably formed of a wood suitable to such use such as spruce wood. Applicantprefers to construct the device of this material but it is of course to be understood that he does not limit himself-to the'use-of this material.

I-I aving thus described my invention, what "I claim is:

1. A loud speaker comprising nested and relatively spaced inner, outer and intermediate horn members of polygonal formation .in cross section and arranged-to position the corners ofthe intermediate member at points between the. corners of the other members.

2. A loud speaker comprising nested and relatively spaced inner, outer and intermediate horn members of polygonal formation in cross section and of different lengths, the

.horn membersbeing arranged to position the corners of the intermediate member at points between the corners of the other members.

3. A loud speaker comprising a casing, and nested and relatively spaced inner, outer and intermediate horn members, the casing and horn members being of polygonal formation in cross section and arranged to position the corners of the outer horn member at points between the corners ofthe casing and toposition the corners of the intermediate horn ,men' ber at points between the corners of the outer and inner hornmembers.

4. A loud speaker of the character set forth comprising a horn casing of square cross section, a plurality of nested horn like members within said casing each ofsquare crosssectional design and comprising anout- .er, an interinediate and an inner member, said ,outer member being arranged to locate the ,cdgesthereof upon the longitudinal center of thecasing walls, said intermediate member being arranged to locate its edges upon the longitudinal center of theouter member walls andsaid inner member being arranged to locate itsedges adjacent the longitudinal centersoftheintermediate member walls, and a tone arm leading to the inner end of said outer member.

5. A loud speaker of the character set forth .comprisinga horn casing, of square cross section, a plurality of .nested horn like members .WltlllILSitltlfiflSlDg each of square cross-sectional design and comprising an outer, an intermediate and an inner member, said outer member beingarrangedto locate the edges thereof upon the longitudinal center of the Vadjacentithe longitudinal centers of the intermediate member walls, and a tone arm leading to the inner end of said outer member, sound posts connecting the walls of said outer member with the casing, and a sound post structure extending across said intermediate member.

6. A loud speaker of the character set forth comprising a horn casing of square cross section, a plurality of nested horn like members within said casing each of square cross sectional design and comprising an outer, an intermediate and an inner member, said outer member being arranged to locate the edges thereof upon the longitudinal center of the casing walls, said intermediate member being arranged to locate its edges upon the longitudinal center of the outer member walls and said inner being arranged to locate its edges adjacent the longitudinal centers of the intermediate member walls, a tone arm leading to the inner end of said outer memher, said intermediate horn member being of materially less length than the outer member, and said inner member being of substantially half the length of the intermediate member.

7. A loud speaker of the character set forth comprising a horn casing of square cross section, a-plurality of nested horn like members within said casing each of square cross-sectional design and comprising an outer, an intermediate and an inner member said outer member being arranged to locate the edges thereof upon the longitudinal center of the casing walls, said intermediate member be ing arranged to locate its edges upon the longitudinal center of the outer member walls and said inner being arranged to locate its edges adjacent the longitudinal centers of the intermediate member walls, a tone arm leading to the inner end of said outer member, said intermediate horn member being of materially less length than the outer member, and said inner member being of substantially half the length of the intermediate member, said inner member having the walls thereof in materially sharper divergent relation than the Wall of the other members.

In testimony whereof I affix my signature.

ANDREW 'DELPH. 

